He then apologised to Hayleigh and Chaise for what he had done, before calmly leaving the flat.

When the couple went into the living room, they found an horrific scene. Sabrina was lying naked on the kitchen floor, bleeding to death.

Chaise rushed to Sabrina’s side to try and administer first aid, but she only had just enough time to utter Hayleigh’s name before she died.

Sabrina, right, with her daughter Hayleigh (Picture: PA)

After a trial, jurors at the Old Bailey found Griffin guilty of murder on September 25. He has now been sentenced to life, with a minimum of 16 and a half years in prison.

Detective Chief Inspector Will Reynolds, of the Met Police’s Homicide and Major Crime Command, said: ‘Griffin callously and viciously attacked a vulnerable, trusting woman that he purported to love and had asked to marry him.

‘He subjected her daughter, Hayleigh, and her boyfriend to the terrible ordeal of hearing the attack on Sabrina but being prevented from helping her, and then callously fled the scene.

‘Her death has left the family utterly devastated.

‘I am pleased that the jury did not accept the argument put forward of diminished responsibility and have rightly found Griffin fully accountable for his appalling actions of that terrible night on which Sabrina lost her life.’